Get Bounding Box Lenght Of Curved Road
Install the Measureit addon

For more details watch this video : https://www.youtube.com/watch?v=crMAa5tG-l8
To download : https://github.com/Antonioya/blender/blob/40b63abde362555d0cf3cfb00454f0691871f144/measureit/measureit_v1_6_7.zip